Factual error: When Bruce and Patricia are in a lift after being chased by the cars in the garage, the lift rapidly descends but the two people in the lift are seen struggling on the floor when they should just about be on the ceiling due to the speed of the lift's descent.
Factual error: Towards the end of the movie, Mary sends a hand-written note to Inspector Abberline. The 'r' in her name is written in a North American style, where she is European.
Factual error: Near the end of the movie, Jamie Lee is speeding down a road in the coroner's van she has stolen and Michael is attacking her from the back of the van. She slams on the brakes, and he flies into the front windshield, which shatters into many pieces. Windshields are made of laminated glass, which contains a sheet of plastic, sandwiched between to sheets of glass. It does not shatter when struck.
Factual error: Spoiler: In the scene toward the end of the movie when the dad is burned alive, his skin is completely black but his clothes are still on and intact, just blackened. With fire hot enough to completely blacken the skin, it would have burnt the clothes completely off (or at most they would have been shredded rags). (01:51:25)
Factual error: There is one scene in the movie where Heath Ledger reads a Latin sentence in a book. As he is translating the sentence, he goes over the words one by one with his finger. This would never be possible in a Latin sentence, because words in Latin are never - I repeat: never - in exactly the same order as in English. Words that actually belong together can be placed on opposite ends of a sentence.
Factual error: In order to be electrocuted you need to connect a high voltage to a low voltage. Touching a power line does not get you electrocuted unless you make contact with the ground. So electrocuting the locusts by making them fly against a powerline can not work because they are not 'grounded'.
Factual error: The geography of London is all wrong. When Howard Keel leaves the Eye Hospital (in Kings Cross) he turns a corner and ends up in Lincoln's Inn Fields (where he sees a dog being killed by a Triffid), he then exits the park and ends up in Victoria Train Station. All these locations are several miles apart.
Factual error: In the very beginning of the film, the priest is walking through a battlefield that contains the bodies of Roman soldiers (they are wearing distinctive Roman uniforms and armor), which dates the battle no later than 6th century AD. He is holding a rosary in his hand, but the rosary wasn't introduced into the Catholic Church until the 13th century.
Factual error: In the 30th Anniversary version with new footage it is revealed that the first zombie we see (the one that kills Johnny) died in the electric chair. If that's the case, he should be bald with a large burn on his scalp, but he has a full head of hair. If he died in the electric chair then he shouldn't even have reanimated, as the method of electrocution kills by cooking the brain.
Factual error: According to netstate.com the average monthly high in the state of Louisiana is 93.3 degrees F (34.05 degrees C) with summer months often exceeding 100 degrees F (37.77 degrees C), making it impossible for a functional multi-story wax structure to remain functional for any extended period of time, regardless of wax content.
Factual error: During the Mars-flight, the way the spacecraft uses the rocket thrusters is unrealistic. For example when they are nearing Mars, they should be using the rockets against their movement, to slow down the speed. But in the movie they are using the rockets towards Mars.
Factual error: The Sensory Deprivation Tank used in the film is an MRI machine. It has no doors and makes far too much noise to allow for sensory deprivation. (00:47:15)
Factual error: In the beginning of the movie, the killer calls Cotton on his cell phone. When the killer hangs up on him, you hear a dial tone. When someone cuts you off on a cell phone, you don't get a dial tone. (00:02:40)
Factual error: During the scene where Peyton is hanging from the helicopter, Durant is firing at him with a grenade-launcher. He hits several cars, most of which end up in flaming wrecks. Despite this, traffic continues as normal... If you saw cars around you exploding, would you casually continue on, oblivious? This error is especially visible with the truck driver, whom reacts to Peyton landing on top of his truck, but seems oblivious to the chaos behind him.
Factual error: The crew gasses out the ant hill by dropping chemical grenades into the hole. But there are two reality mistakes about the grenades: 1) chemical grenades do not explode; they spray their contents into the area; and 2) considering the size of the ants, the size of their nest must be gigantic, and therefore, it would take more than a hundred grenades to flood it completely with cyanide gas.
Factual error: When the FBI agents are shooting Jason, 2 things happen that shouldn't, 1. His machete is shot but doesn't move, the force from the bullet would cause the knife to move. 2. When the bullets hit the knife, they cause sparks, bullets never cause sparks when they hit metal.